Bone marrow biopsy needle with cutting and/or retaining device at distal end

ABSTRACT

A bone marrow biopsy needle provided with blades which cut and retain a biopsy core. In one embodiment, the cutting blades of the needle are hinged at the distal end of the needle and are mechanically coupled to an actuator at the proximal end of the needle. The needle is preferably formed with inner and outer walls to provide a space therebetween for the mechanical coupling. The cutting blades are retained in a dead space against the outer wall of the needle when the needle is open. In lieu of a hinged arrangement, the outer wall of the needle may be tapered at its distal end so that the blades are forced together when they are pushed forward. In another embodiment, the cutting blades are pre-curved inward, but are retained against the inner surface of the needle wall until pushed forward. In yet another embodiment, the distal ends of the cutting blades rest within a curved circumferential recess provided in the needle wall, and, when pushed forward, move together to cut and retain the biopsy core.

This is a continuation of application Ser. No. 08/548,588, filed on Oct.26, 1995, now U.S. Pat. No. 5,583,628, which is a division ofapplication Ser. No. 07/863,457, filed Apr. 6, 1992, now U.S. Pat. No.5,462,062, which is a continuation-in-part application of Ser. No.07/806,486, filed on Dec. 13, 1991, now abandoned.

BACKGROUND OF THE INVENTION

When a bone marrow biopsy is performed, a biopsy core, which consists ofa plug of bone and marrow, is withdrawn with a bone marrow biopsy needlefrom the body of the patient. At times, it is difficult to retain thebiopsy core in the needle while the needle is being withdrawn from thepatient.

FIG. 1 is a schematic cross-sectional view of the known Jamshidi® bonemarrow biopsy needle, which is available from Baxter Healthcare Corp. Acylindrical needle 20 tapers slightly at the distal end 22 to form anarrowed tip. An inner trocar or introducer 24 must be inserted andsecurely retained in the needle 20 during insertion into the patient.The trocar 24 has a chisel-like tip 26 which aids the needle topenetrate the patient's bone. After the bone is pierced, the trocar isremoved rearwards from the needle and insertion of the needle continuesin order to collect the desired biopsy core within the needle. Becauseof the inward curve of the end 22, the needle 20 has a cylindrical "deadspace" 28, which is not usable to contain the biopsy core.

With the Jamshidi® needle, it is difficult to keep the solid biopsymaterial in the needle as the operator is withdrawing the needle fromthe patient. A biopsy core approximately 11/2 inches (3.8 mm) isgenerally needed. Conventionally, it is necessary to shake the needlefrom side to side, to break the biopsy core loose from the adjacentmarrow. This agitation of the bone marrow is uncomfortable for thepatient. It also may create a risk of metastasizing malignant cancer,leukemia, or lymphoma cells which are infiltrated in the marrow of thepatient, because the bone marrow is highly vascular. The marrow containsa vascular system which is quite complex and includes a vascularsinusoidal system. See Wintrobe, M. M., et al., eds., ClinicalHematology (Lea & Febiger 1981); Anat. Rec. 68:55 (1970); and Weiss,L.,"Histopathology of the Bone Marrow," in Regulation of Hematopoiesis,A. S. Gordon, ed., (Appleton-Century Crafts 1970).

Therefore, it would be desirable to provide some means of separating orcutting the biopsy core from the surrounding marrow in order to free itfor removal, without unnecessary agitation of the marrow. Such a devicewould be effective to reduce or eliminate risk and discomfort for thepatient.

Another problem with the prior art needle is that, even after the biopsycore is broken loose from the bone marrow, it sometimes falls out of theneedle as the needle is being withdrawn from the patient's body. Thus,there is a need for a biopsy needle having a closable distal end forretaining the biopsy core in the needle.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a bonemarrow biopsy needle with a device at the distal end of the needle thatcan be actuated by the operator at the proximal end of the needle, forcutting off the biopsy core from the adjacent marrow, before it iswithdrawn from the patient.

Another object is to provide a device for retaining the biopsy corewithin the needle as the needle is withdrawn from the patient, such as adevice for closing the distal end, or another type of retaining device.

With the invention, it is no longer necessary to shake the needle beforewithdrawal in order to break loose the biopsy core from the underlyingmarrow, and the core is reliably retained in the needle duringwithdrawal. Discomfort and risk to the patient are substantially reducedor eliminated.

Thus, the disclosed embodiments of the invention are a markedimprovement over all previous needles, including the Jamshidi® andJamshidi-type needles, and the Gardner, Silverman, Bierman, Conrad,Crosby, Westerman-Jensen and Osgood types of needles.

Other features and advantages of the present invention will becomeapparent from the following description of the invention which refers tothe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of the known Jamshidi® bonemarrow biopsy needle which is available from Baxter Healthcare Corp.;

FIGS. 2A and 2B are respectively a schematic cross-section and an endview showing a first embodiment of the invention;

FIG. 2C is a schematic cross-section showing a modification of theforegoing embodiment;

FIGS. 3A and 3B are, respectively, a schematic cross-section and an endview showing a second embodiment of the invention in the open position,and FIGS. 3C and 3D show the second embodiment in a closed position;

FIG. 4A is a schematic cross-sectional view and FIG. 4B is an end view,showing a third embodiment of the invention, wherein the relativedimensions and arrangement of the parts are greatly expanded forclarity, and FIGS. 4C and 4D are schematic cross-sectional views showingthe third embodiment provided with a wire arrangement for closing theblades of the needle;

FIGS. 5A and 5C are schematic cross-sectional views, respectively,showing an open and a closed position of a fourth embodiment of theinvention, FIGS. 5D and 5E are corresponding end views, and FIG. 5B iscross-sectional detail of a hinge which is usable in the fourthembodiment;

FIGS. 6A and 6B are schematic cross-sections of a fifth embodiment ofthe invention, in open and closed positions, respectively; and

FIGS. 7A and 7B are schematic cross-sections, and FIGS. 7C and 7D areend views, of a sixth embodiment of the invention, in open and closedpositions, respectively.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Referring to FIGS. 2A and 2B, a first embodiment of the invention isillustrated, in which a needle 30 is provided with a sharp cutting edge32 at its distal end, the needle being turned back inward from thedistal end to form an inner "cuff" or flange 34 with a sharp, inwardlydirected edge 36. The inwardly directed, angled flange 34 issubstantially immobile and helps to retain the biopsy core in theneedle. Also, the inner edge 36 helps to cut off the biopsy core withonly a slight amount of horizontal and/or vertical movement of theneedle.

FIG. 2C shows a variation on the foregoing embodiment, wherein, inaddition to the flange 34, the needle 30' has a roughened or toothedregion 38 just behind the flange 34 which improves the retention of thebiopsy core in place while it is being cut by the edge 36 and thenwithdrawn.

FIGS. 3A and 3B show, respectively, a schematic cross-section and an endview of a second embodiment of the invention. A needle 40 has a pair ofopposed hinges 42a, 42b at its distal end, and a pair of sharp-edgedblades 44a an 44b are attached to the hinges at opposite sides of thedistal end of the needle. As it is inserted into the patient, the biopsyneedle 40 receives the biopsy core 46. Then, as the needle is beingremoved from the patient, as shown in FIGS. 3C and 3D, as soon as theneedle is pulled slightly outward, the biopsy core 46 engages the sharpinner edges of the blades 44a and 44b, thereby closing the blades inorder to both cut off the biopsy core and retain it in the needle.

As shown in FIGS. 3A and 3C, a pair of actuating wires 43a and 43b,attached to the blade mechanism, can be provided within needle 40. Whenwires 43a and 43b are pulled, blades 44a and 44b close, thereby cuttingthe biopsy and retaining it in place within the needle.

Although the embodiment of FIGS. 3A-3D has two opposed blades, oneblade, or a larger number of blades, can be used. For example, theneedle can have an iris arrangement of blades, similar to that disclosedbelow in connection with FIGS. 4A and 4B.

FIG. 4A is a cross-sectional view showing a third embodiment of theinvention, wherein the relative dimensions and arrangement of the partsare greatly expanded for clarity. In this embodiment, a needle 50 isprovided with an outer cylindrical wall 52a and an inner cylindricalwall 54b. The wall 52a tapers at the distal end of the needle and curvesinward to a sharp circular tip edge 54. The walls 52a and 52b are heldtogether, for example, by radial spacers 56, two of these being shownschematically in FIG. 4A. The inner wall 52b ends short of the distalend of the needle and does not substantially curve inward. Near the endof the wall 52b is a series of hinges 58 (six in this embodiment)extending circumferentially around the interior of the needlesubstantially between the walls 52a and 52b. Attached to the hinges 58are a series of six blades 60a-60f, which form an iris arrangement asshown in FIG. 4B. Blades 60a-60f have sharp distal edges.

As shown in FIG. 4A, in their initial position, the blades are locatedcompletely within the cylindrical "dead space" of the outer wall 52a asindicated by the dotted line DS. Therefore, when the needle is insertedinto the bone marrow, the iris 60 presents no obstruction to the entryof the marrow core. When the needle has been inserted and the biopsy isready to be withdrawn, the blades of the iris 60 are then closed byrespective wires attached to the blades 60a-60f, which are pulled by anappropriate pulling device at the proximal end of the needle (notshown). In FIG. 4A, only wires 62a and 62d are shown. The blades of theiris close, cutting off the distal end of the biopsy core and alsohelping to retain it within the needle 50.

In an alternate embodiment, shown in dashed lines in FIG. 4B, one ormore wires may be threaded over the outside of the hinges 58, beingguided essentially axially over the hinges. Then, each wire is guidedthrough a guide loop or the like at the inner edge of one blade, orseveral blades, and is secured near the inner edge of a last one of theblades. In this embodiment, pulling on the wires closes the blades andcuts off and secures the biopsy core. Alternatively, the wire-threadingarrangement shown in FIGS. 4C and 4D can be used, in which one wire 69extends circumferentially around the iris 60, joining all the blades60a-60f. Wire 69, when pulled, acts simultaneously on all the blades toclose the iris.

Instead of employing wires which pull on the blades in order to closethem, the blades may alternatively be closed by rods or the like whichpush on portions of the blades. Further, a detent mechanism (describedbelow in connection with FIGS. 5A and 5C) may be employed to guide theoperator as to how far the rods should be pushed in, and to maintain therods in position.

FIGS. 5A and 5B show a fourth embodiment of the invention in which abiopsy needle 70 includes an outer tube 72 with an inwardly tapered end74, and an inner tube 76 with a pair of opposed blades 76a, 76b whichare hinged to the inner tube 76 by hinges 77a, 77b at its distal end.The inner tube 76 is slidable axially within the outer tube 72. Theouter and inner tubes 72, 76 have respective operating flanges 75a, 75bat their proximal ends.

While inserting the needle 70 into the patient, the operator presses onthe operating flange 75b. The flanges 75a, 75b are separated by two ormore blocks 73a, 73b to keep the inner tube from sliding into the outertube. Then, when the biopsy core has entered the needle, the blocks 73a,73b are removed and the inner tube 76 is pressed axially into the outertube 72. The blades 76a, 76b engage the tapered end 74 and are directedradially inward, as shown in FIG. 5C, thereby simultaneously cutting offthe biopsy core and retaining it in the needle 70.

The needle 70 can optionally include a detent arrangement 78, shown inFIG. 5C, in which a small, outwardly curved segment or bulb 78a isprovided on the inner tube 76 and a recess 78b of the same shape isprovided on the outer tube 72. When the bulb 78a enters the recess 78b,it clicks in place, signalling the operator that the inner tube 76 hasbeen pushed the proper distance into the outer tube 72, and helping tomaintain the relative position of the inner and outer tubes 72, 76. Toremove the biopsy (after the needle has been withdrawn from thepatient), the operator squeezes operating flange 75, thereby releasingbulb 78a from recess 78b, allowing the inner tube to be slid back,opening blades 76a and 76b.

FIGS. 6A and 6B are schematic cross-sections illustrating a fifthembodiment of the invention, in which a needle 80 is provided with adistal, pre-curved metal blade 84 actuated by a proximal knob 82.Pre-curved metal blade 84 is sufficiently flexible to be held in placeagainst the inner surface of needle 80 by very small clips (not shown).When blade 84 is moved inward by pushing on proximal knob 82, its distalend moves beyond the clips and is no longer held against the inside ofneedle 80. Since blade 84 is pre-curved, it moves inward as shown inFIG. 6B, cutting the biopsy sample and closing the entrance to theneedle, thereby preventing the biopsy from falling back out of theneedle 80. Since the blade 84 is initially held parallel and close tothe inner wall of the needle 80 by the clips, biopsy material cannotbecome lodged between the blade 84 and the needle wall 80 when thebiopsy is entering the needle. As shown in FIG. 6B, a detent arrangement86 can be used in the same manner as in the previous embodiments tosignal the operator when the blade is in the correct fully insertedposition and to maintain the blade in that position.

FIGS. 7A and 7B are schematic cross-sections, and FIGS. 7C and 7D areend views, of a sixth embodiment of the invention, in which a pair ofpre-curved blades 94a and 94b are fit into a curved circumferentialrecess 92 in the needle 90. After the biopsy is inside the needle 90,the blades 94a and 94b are advanced, cutting the biopsy and retaining itin place. The blades 94a and 94b are pre-curved at an angle so as tomeet each other when pushed forward. Since the needle 90 need only beinserted into the patient up to, but not including, the recess 92, the"bulged" portion of the needle never enters the patient; thus, there isno "wider hole" or extra discomfort to the patient. As before, theneedle 90 can be provided with a detent arrangement to ensure that theblades 94a and 94b are advanced to the proper position.

Although the present invention has been described in relation toparticular embodiments thereof, many other variations and modificationsand other uses will become apparent to those skilled in the art. It ispreferred, therefore, that the present invention be limited not by thespecific disclosure herein, but only by the appended claims.

What is claimed is:
 1. In a bone marrow biopsy needle comprising a tubewhich extends from a proximal end to a distal end and having an openingat the distal end for receiving a biopsy core when the needle isinserted by an operator into the bone marrow of a patient, theimprovement comprising an annular cutting means attached to the interiorof said tube and extending about the tube at the distal end and operablefor cutting the biopsy core from the bone marrow while the biopsy needleis present in the bone marrow, wherein the cutting means includes aninner flange which extends from the distal end toward the proximal endof the tube and has a sharpened cutting edge at a proximal end of theflange.
 2. A needle in claim 1, further comprising a sharpened cuttingedge at the distal end of the needle.
 3. A needle as in claim 1, whereinthe inner flange is attached to the tube at the distal opening.
 4. Aneedle as in claim 1, further comprising gripping means on an inner wallof the tube and spaced from the distal end, for gripping the biopsycore.